Propulsion of steam vessels.



N0. 7|2,7|3. Patented Nov. 4, I902.

C. A. PARSONS.

RROPULSION 0F- ST EAM VESSELS.

(Application filed Jan. 28,- 1901.,

(No Model.)' 4 Sheets-Sheet THE mam; Pzrzas ca, PHOTD-LITHO. WASHINGTON,D. c.

Patented Nov. 4, I902.

c. A. masons.

PROPULSION 0F STEAM VESSELS:

(Application filed Jan. 28, 1901.;

4 SheetsS'h,eet 2.

(No Model.)

TNE NORRIS PETERS c0. PHOYO-LITHO wAs-uu Qn, 1:, c.

, N0. 7|2,7I3. Patented Nov, 4, I902. C. A. PARSONS.

PROPULSION 0F STEAM VESSELS.

Application fi led Jan. 28 1901.,

4 Sheets-Sheet 3.

(No Model.)

Mamie-sf? Parse/3 m5 NORRIS PETERS c0, PNOTGLITHQ, WASWNGTON. n c.

Patented Nov. 4, I902.

C. PARSONS. PROPULSION OF STEAM VESS'ELS.

' (Application filed Jan; 28, 1901.,

4 Sheets-Sheet 4 (No Model.)

QI IHHHH I HUH HI I I HHI WM 1 h iny an a/ Z5.

m: Noizms PETERS FNOTO-L'ITHO WASHINGTON, n4 0.

ilNrrnn rates ATENT Fries.

CHARLES ALGERNON PARSONS, OF NEWCASTLE-UPON-TY NE, ENGLAND.

PROPULSION. OF'STEAM VESSELS.

SPECIFICATION" forming part of Letters Patent No. 7l2,713, datedNovember 4, 1902.

Application filed January 28,1901. Serial No. 45,163. (No model.) I

To 00% whom it may concern:

PARSONS, a subject of the King of Great Britain and Ireland, residing atHeaton Works, Newcastle-upon-Tyne, in the county of Northumberland,England, have invented certain new and useful Improvements in thePropulsion of Steam Vessels, (for which I have made application forpatent in Great Britain, No.

16,551, dated September 17, 1900,) of which the following is aspecification.

My invention relates to the application of the system of combiningreciprocating engines with steam-turbines for the purpose of gainingincreased economyin steam consump-- tion.

My present invention has for its object to enable the highest degree ofeconomy of steam consumption to be attained, both at cruising and atfast speeds; and this involves the use of highly-developedcondensing-turbines having a range of expansion of from fifty to onehundred and fifty fold when working at full power.

I have experimented with turbines to determine the horse-power necessaryto rotate the turbine with no steam passing through it and with variouspressures, from atmosphere downto an absolute pressure of one pound persquare inch in the turbine-case, and also at various speeds ofrevolution. I have found that taking my condensing type of turbinedesigned for high ratios of expansion and high steam efficiency undernormal conditions of working when the steam-turbine is driven idly up toone-half its normal speed of working in a good vacuum the power requiredto rotate it is only about one per cent. of the normal full power outputof the turbine and varies approximately as the cube of the speed ofrotation.

I am well aware that many attempts have been made to place tworeciprocating engines of greatly different size and power to rotate thesame screw-shaft; butin consequence of the great frictional resistanceto rotation of a reciprocating engine, commonly called the idlefriction, it has been found necessary to place the smaller engine abaftthe larger one and when cruising speeds are required to entirelydisconnect the larger engine from the screw-shaft, which is then drivenby the Be it known that I, CHARLES ALGERNON' smaller engine only. \Vhenhigher speeds are required, the larger engine is coupled up, and thelarger alone, or both engines combined, drives the screw-shaft. Thedifficulty of coupling and uncoupling the nearly full horse-power of thevessel has been such as to render this arrangement unsatisfactory in useas also the added difliculty of transmitting the full power through thesmall engineshaft. Further, owing to the high value of the idle frictionsuch an arrangement does not give the increased economy which was aimedat and which is attained by my present invention.

In my invention, as above stated, it has been found that the frictionalresistance or idle friction required to rotate the main turbine in thevacuum is so small that the turbine can be left permanently coupled tothe screw-shaft to which the reciprocating engine is coupled. Further,the power transmitted by the reciprocating engine is comparatively sosmall that a suitable coupling, which can be easily thrown into and outof gear, can be satisfactorily used-such, for example, as a frictioncoupling operated by hydraulic power. In the case of high-speed vesselswhere the speed of rotation of the turbines at full speed is too highfor the reciprocating engine to work satisfactorily I use a detachablecoupling, which can be easily thrown out of gear; but in cases where thefull speed of the turbine is not too high for the reciprocating enginethe latter may, if desired, be left permanently coupled.

The first part of my invention therefore consists in propelling a steamvessel by means of one or more propeller-shafts driven by a combinationof one or more highly-efficient multiple expansion reciprocating enginesadapted to give the power required forcruising speeds, with one or morecondensing-turnines having a high range of expansion operating on one ormore of the said shafts and adapted to develop the whole or the greaterpart of the power required for the fast speeds, so that the highesteconomy of steam consumption is attained both forcruising and fastspeeds, the main turbine being run in the condenser-vacuum when thereciprocating en- ICO gine is alone propelling the vessel. Thereciprocating engine may be coupled so that it can be disconnected, ifdesired.

I have further found by experiment that when a turbine of the condensingtype is driven by external power in a good vacuum and when smallquantities of steam are admitted at the inlet and flow through theturbine to the condenser the power required to rotate the turbine fallsapproximately as the amount of steam admitted up to the no-load amountfor that speed and that when the quantity has increased up to thatamount the turbine rotates itself at the given speed without anyexternal power and for larger, but still relatively small amounts, givesoutpower on the shaft.

The second part of my invention therefore relates to the combinedsteam-turbines and reciprocating engines dealt with above, and consistsin passing the steam from the cruising-speed reciprocating enginesthrough the main steam-turbine on its way to the condenser, thereby notonly reducing the resistance to rotation of the said main turbine, butalso in almost all cases adding considerably to the power developed, andthus economizing the steam required for propulsion at cruising speeds.The steam so admitted, however, may not in some cases be sufiticient todirectly apply power to the shaft, but may simply act to reduce theresistance to propulsion of the vessel.

My invention also comprises the complete combination of steam-turbineand reciprocating engine with steam-pipes connecting the exhaust of thereciprocating engine with the main steam-turbine inlet and then with thecondenser, instead of each delivering into the condenser direct.

In applying my invention to war vessels, where economy of steam atcruising speeds and also at fast speeds is of great importance, I preferto connect the exhaust or exhausts of the reciprocating engine orengines into themain turbines, preferably at their main steam-inlet. Inthis arrangement when cruising speed is required the steam may beexpanded from full boiler-pressure, the first stage being in theordinary reciprocating engine of the compound or triple expansion typeand then through the main steam-turbine right down to thecondenser-vacuum, the result being a very high degree of steamefficiency. \Vheu the high speeds have to be attained, the steam isadmitted direct to the main turbine and passes thence to the coudenser.Thereciprocatingeuginesandsteamturbines may drive the same or differentshafts, and the pistons and cranks of the reciprocating engine orengines may operate on one or more of the screw-shafts.

Referring now to the accompanying four sheets of drawings, whichillustrate, by way of example, two modifications of combined turbine andreciprocating engines adapted to propel a war vessel economically, bothat cruising and at full speeds, by means of three propeller-shafts,Figure 1 shows in elevation, and Fig. 2 in plan, one combination andarrangement of turbines and reciprocating engines. Fig. 3 shows inelevation, and Fig. 4 in plan, another combination and arrangement. Theelevations are partly in section along the longitudinal midship-sectionof the vessel.

In Figs. 1 and 2 this invention is shown applied to a war vessel of twothousand tons displacement, ten thousand indicated horsepower, andtwenty-two knots speed. The high-pressure turbine at is placed alone onthe central shaft 1 and exhausts into the two low-pressure turbines band c on each side, mounted, respectively, on the side shafts 2 and 3.On the ends of each of these shafts I couple multiple-expansionreciprocating engines d and e by means of suitable hydraulic or othercouplings f and g, where the speed of the turbine set at full load ishigher than that of the reciprocating engines. Where these speeds arethe same, however, the shafts may be rigidly coupled. At full speedthepowers developed in the three turbines are preferably approximatelyequal, and the speed of the outside shafts 2 and 3 is seven hundred,while that of the center shaft is five hundred, revolutions per minute.The shafts 2 and 3 each-carry two. propellers, while the center shaftcarries only one. At cruising speed, however-say twelve knots perhour-with a boiler-pressure of two hundred and twenty five pounds persquare inch, I find that I can obtain in the reciprocating engines anexpansion of about fifteenfold, While in the turbines running at thespeed of the reciprocating engines I attain another fifteen-foldexpansion down to the condenser-pressure of about one pound absolute.Under these conditions the reciprocating engines develop about sixty percenti of the power required, while the turbines ive the remaining fortyper cent. I utilize a combi nation of this character to the bestadvantage for fast speeds by simply uncoupling the reciprocating enginesand admitting the boiler-steam by way of pipe 4 and valve 5 direct intothe high-pressure turbine at on shaft 1. This then exhausts intothe twoturbines b and c by way of pipes 6 and 7 and from these into thecondensers h and t' by pipes 8 and 9. The turbines a, b, and 0 form aset which are capable of dealing with steam at full boiler-pressure andeifecting the required manifold expansion, so.that economical working isobtained at full load. I Economicalpropulsion at cruising speeds isobtained by coupling up the reciprocating engines d and e by theirhydraulic or other couplingsfandg to their respective'shafts. Thereciprocating engines in this case develop their fulleconomical power ata speed of rotation of about three hundred revolutions per minute-t. e.,

- and thirty revolutions per minute.

indicated horse-power, of which the recipro eating engines will produce,say, about six hundred and the turbines four hundred. In

one way of working the turbines 0,, b, and c are all simply run in thecondenser-vacuum, and the engines (:1 and e exhaust in that case by wayof pipes 10 and 11 direct to the condensers h and 7 respectively. Thehighest economy is obtained while cruising by passing the exhaust-steamfrom the reciprocating engines 61 and e by way of pipes 12 and 13 to theturbine at and thence by way of the pipes 6 and 7 through turbines b andc to the condensers h and 2'. It will be seen that while cruising thusthe central shaft 1 is caused to rotate by the motion of the vesselthrough the water acting on its propeller, and this to some slightextent causes added resistance of the vessel to propulsion. By admittingthe exhaust-steam from the reciprocating engines to the turbine a I notonly cancel this added resistance either partially or wholly, but inmost cases add a very large -fraction to the power available forpropelling the vessel.

It will be obvious that in my new system of propulsion when runningatcruising speeds the exhaust-steam from the reciprocating engines isutilized not only in reducing the idle .friction of the turbines andshafts, but generally and in almost all cases and circumstances topositively'increase the torque by a very large amount, although the mosteconomical turbine speed is not attained.

In cruising the steam at full boiler-pressure is admitted to thereciprocating engines and is preferably expanded by them to somewhatabove atmospheric pressure. It then enters the high-pressure turbine at,and thence passes through the two low-pressure turbines b and 0 on itspassage to the condensers. The vacuum in the condensers under theseconditions at cruising speeds is abnormally high, and ratios ofexpansion of from two to three hundred fold are practically attainable.

In Figs. 3 and 4 a modified arrangement of combined turbines andreciprocating engine is shown suited for a vessel of similar power andspeed. I Iere only one reciprocating engine k is provided. It is placedon the central shaft 1. Its power should be about equal to the combinedpower of the reciprocating engines d and e in the first case, and it maybe run at a slower speed than the two reciprocatin g engines (1 ande-say at two hundred In this case at cruising speeds the turbines b andc are rotated by the motion of the vessel through the water, and theconsequent resistance is nullified, as before, either by opening theturbines b and c to the condenser-Vacuum or more economically by theadmission of the exhauststeam from the reciprocating engine through theturbine sets on the Way to the condenser. This invention enables veryslow speeds also to be obtained with much greater economy thanispossible with existing. engines. The main air-pumps in such plants arepreferably worked in the usual way by worm-gearing from the mainturbine-shafts.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is-- 1. A system of engines forpropellingsteam vessels comprising, a reciprocating engine adapted to propel thevessel at cruising speeds, a turbine engine adapted to alone propel thevessel at full speed, shafting to which the engines are connected, andcondenser means to produce condenser-vacuum in which the turbine runsidly when the reciprocating engine is alone employed for propelling thevessel at cruising speeds,substantially as described.

2. A system of engines for propelling steam vessels comprising, areciprocating engine.

adapted to propel the vessel at cruising speeds, a turbine engineadapted to alone propel the vessel at full speed, shafting to which theturbine is permanently connected, and a condenser for producing acondenser-vacuum in which the turbine runs idly when the vessel is beingpropelled at cruising speed'by the reciprocating engine alone,substantially as described.

3. In combination, a reciprocating engine, a low-pressure turbine, apropeller-shaft driven by the said turbine, a high pressure turbine, apropeller-shaft driven by the highpressure turbine, anexhaust-steam-supply connection from the reciprocating engine to thehigh-pressure turbine,- and an exhauststeam-supply connection from thehigh-pres sure turbine to the low-pressure turbine, sub stantially asdescribed.-

4. In combination, a reciprocating engine, a high-pressure turbineconnected with the exhaust thereof and having a shaft, a direct steamconnection leading to the high-pressure turbine, a low-pressure turbine,a shaft for said low-pressure turbine, a steam-supply pipe from thehigh-pressure turbine to the low-pressure turbine and detachablecoupling means by which the reciprocating engine may be thrown out ofconnection, substantially as described.

5. A combined set of reciprocating engines and turbines adapted topropel a vessel economically at both fast and cruising speeds, andconsisting of a high-pressure turbine driving a central shaft, twolow-pressure tur bines, coupled in parallel, each driving one of twoouter shafts; these shafts each having detachably coupled to it'amultiple-expansion steam-engine for the same or lower speed.

6. A combined set of turbines and recipro= eating engine adapted topropel a vessel eco IIO nomically at both fast and cruising speeds inparallel, the two outer and consisting of a highpressure turbine drivinga central shaft and two low-pressure turbines coupled in parallel, eachdriving one of two outer shafts, said central shaft having detachablycoupled to it a multiple-expansion steam-engine for the same or lowerspeed.

7. A set of turbines and reciprocating engines for propelling a vesselconsisting in a high-pressure turbine, a central shaft driven thereby,two low-pressure turbines coupled shafts driven by said low-pressureturbines and a reciprocating engine connected with the shafting,substantially as described.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

CHARLES ALGERNON PARSONS.

Witnesses:

HENRY GRAHAM DAHYM, WILLIAM DAGGETT.

